Acid of the norpinane series



Patented Sept. 16, 1947 2,427,344 ACID or run NORPINANE scams 1 Joseph P. Bain, Jacksonville, Fla., assignor, by mesne assignments, to The Glidden Company, Cleveland, Ohio, a corporation of Ohio N Drawing.

Original application January 6,

1944, Serial No. 517,218. Divided and this application August 12, 1946, Serial No. 690,076

1 Claim. 1

The present invention relates to new compounds of the pinene group, and to the production of the same, and is a division of my copending application Serial No. 517,218, filed January 6, 1944, for Compounds of the norpinane series HrC H The alcohol has the .iollowlng approximate characteristics B. P. at 10 mm C 110-l12 Refractive index (N 1.49-1.493 Density at 25 C 0963-0964 Optical rotation degrees -35 to ---37 Since the product is prepared from nopinene and is an alcohol, it will be referred to as nopol.

It, and certain of its derivatives may be considered as apopinene compounds, but since there is no established numbering system for apopinane applicant will herein consider the compounds as being substituted norpinane compounds, the numbaring system for norpinane being:

Norpinane Beta pinene, according to this system is 6,6 dimethyl-2 methylene-norpinane, and nopol is B(6,6 dimethyl norpin-2-ene-2-) ethanol.

It has been found that the double bond of nopol may be hydrogenated to produce a new series. of compounds of the pinane group. Such compounds do not exhibit the tendency to thermal isomerization shown by nopol and its esters. Also the new compounds do not in general exhibit the pinene reactions which are exhibited by nopol and its esters. .Also the new compounds do not in general exhibit the pinene reactions which are exhibited by nopol and its esters. The new compounds are therefore more stable. Primary terpene alcohols as well as terpene acid and aldehydes are useful in the medicinal, insecticidal and other fields and the stable products of the present invention are useful in such fields.

Example I Example II 322 grams of nopol was hydrogenated at 1000 to 1500 lbs/sq. in. pressure in the presence of 5 grams of Raney nickel catalyst at a temperature of -200 C. In 4.5 hours the alcohol had absorbed 44.1 liters of hydrogen and reduction was discontinued. The one double bond in this quantity of nopol theoretically requires the absorption of 43.4 liters of hydrogen. The product was then fractionated at 10 mm. pressure. The yield of hydronopol, B (6,6 dimethyl norpinane-2) ethanol, was 270 g., or 80.5% of theoretical, having a boiling point at 10 mm. of 123-125 0., N5 =1.487-2--1.4878, and optical rotation =-2'7.53. The density at 25 C. was 0.961.

Example III 56 grams of hydronopol were dissolved in glacial acetic acid. A cool solution of 55 grams of chromium trioxide in 400 cc. acetic acid and 50 cc. of water was gradually added, the solution be- 1 Calculated to standard conditions of temperature and pressure.

ing cooled to keep the temperature below 60 C.

4 tion product in water and adding sodium carbonate the pure aldehyde was liberated. It yielded a semi-carbazone of melting point 161-161.5 0., (alpha) 19.0. (2.0% in isopropanol).

The foregoing reaction are illustrated in the following scheme in which the alpha pinene structure of nopol is employed. As indicated therein, the salts and esters of the novel acid may be formed by conventional methods.

CHzCHaOH CHaCHaOH OH H CH:

' Ha I HC-CH: CH: ---u HC--CH2 CH:

\cm\ \oni i Hl I 41H:

I II

oxidation oxidation CHzCOOX CHaCOOH CHICHO H CH: H CH2 H CH2 Alcohols oxidation He -TECH: CH2 4-B CH2 HO CHCH: CH2

3 ases a \I CH1 CH3 I. Nopoi B (6,6-dimethyl norpin-2-ene-2) ethanol.

II. Hydrooopol B i6,6-dimethyl-norpinane-2) ethanol. III. 6.6 dimethyi norpinane-2-acetie acid.

IV. 6.0 dimethyl ncrpinane-2'acetaldehydc.

V. Esters and salts of 11 solution evaporated. 0n cooling the residue 35 crystallized to give a high yield of the crude hydronopic acid, 6,6, dimethyl norpinane-Z-acetic acid. Recrystallization from aqueous methanol gave the pure acid having a melting point of 5658 C. Neutral equivalent calculated for hydronopic acid, 182.25; found 182.8, 181.8.

Example IV Hydronopol was oxidized to the aldehyde by chromium trioxide in water solution at about 75 C. The alcohol, 168 parts, was stirred with 350 parts water containing 40 parts sulfuric acid. The,temperature of the mixture was raised to '75" C. when 67 parts chromiumtrioxidein 100 parts of water was added. After the reaction was complete the mixture was extracted with hexane and the extract fractionated at 10 mm. pressure. The fragrant aldehyde, 6,6, dimethyl norpinane-2- acetaldehyde, distilled at 95-100 0., N 1.4805, alpha (10 cm. tube)-13.5. For purification it was shaken with a saturated solution of sodium bisulfite, the solid addition product was washed with hexane and dried. On dissolving the addi- A chemical compound having the formula:

H CH:

JOSEPH P. BAIN.

REFERENCES CITED The following references are of record in the 55 file of this patent: 

